Hollow blast-grate.



FATENTED SEPT. 22, 1903.

S. P. GREY.

HOLLOW BLAST GRATE. 7

APPLICATION mm) 001a, 1902.

N0 MODEL.

Sylvester P.Grey

HS NORRIS PETERS co PHOT 7 UNITED STATES Patented September 22 1903.

PATENT OFFICE.

TO JAM ES M. MILLER, OF INDIANAPOLIS, INDIANA.

'HOLLOW'BLAST-GRATE.

SPECIFICATION formingpart'of Letters Patent No.739,4 September 2 1903.

Application fihd October 3, 19oz. SerialNo. 125,751. (No model.)

To all whmn it mwy conoern: I

Be it known that I, SYLvEsTER P. GREY,a,

citizen of the. United States,' residing at Indianapolis, in the county of Marion and State of Indiana, have invented'certain new and useful Improvements in Hollow Blast-Grates, of which the following is a specification.

My invention relates to that class of grates for combustion-chambers known as hollow blast-grates, bymeans of which a blast of air is distributed to various points of the grate beneath the mass of fuel, as may be desired; and said invention consists in 'various improvements in the construction and arrangement of the parts of such a grate, as will be hereinafter more particularly described and claimed.

Referring to the accompanying drawings, which are made a part-hereof, and on which similar reference characters indicate similar parts, Figure l is a side elevation of a furnace having a portion of one side broken away to expose the grate therein, which grate is constructed to embody my present invention, said figure showing also the blast-fan by which the air is supplied to said grate; Fig. 2, a front elevation of said furnace, a portion of said front being broken away to show the grate and other portions of the interior; Fig. 3, aview, partly in top plan and partly in horizontal section, at the point indicated by the dotted line3 3 in Fig. 5, showing the construction more clearly; Fig. 4, a detail perspective viewof assembled fragments of grate-bars, illustrating their form and construction at the rear ends thereof, where they join onto the air-distributing trunk or conduit; Fig. 5, a longitudinal vertical sectional view of one of the hollow grate-bars at either of the points indicated by the dotted lines 5 5 V in Fig. 3; Fig. 6, a detail vertical sectional view as seen when looking in the direction indicated by the arrows from the dotted line 6 6 in Fig. 5, and Fig. 7 a detail transverse vertical sectional View through one ofthe hollow grate-bars as seen when looking in the direction indicated by the arrows from the dotted line 7 7 in Fig. 6. p

The furnace, except in the particulars indicated, is or may be of any ordinary or desiredform or construction and'needs no special description. It has a bridge-wall at the back side of the ash-pit and asuitable I bearing-bar or rest'16 at the front side for the support of the grate-bars at that point. A shoulder formed in the bridge-wall 15 carries the air-distributing trunk or conduit 17, which is shown as rectangular in cross-section and havingopenings in its front sides which register with the hollow grate-bars to be attached thereto. This main distributing v trunk or conduit extends across the furnace and is preferably made insections which are fitted together (preferably telescopically) and when put together should have thinly-mixed fire-clay inserted in the joints to make airtight connections. On itsfrontsiddadjacent to these openings, are tapered wings 18, which receive corresponding flanges on the hollowgr'ate-bars, and at points intermediate said wings are ledges or rest-s 19, which support the intermediate or common grate- ;bars. 'The hollow grate-bars are'composed of main parts extending from the bridge- :wall 15 to the supports 16 and top or cover parts. The main parts 20 are trough-like in form and should taper from the rear to the front ends, so that the cross-sectional area decreases from the point where theair enters to the pointwhere the lastofitfinallyemerges. The top or cover parts 21 of these-hollow grate barsare in the form of rectangular short pieces, as shown, which are laidin end to end, c10se together, and rest ou suitable shoulders in thetops' of the main bar portions 20, and thus completely-coverthe hollow spaces and complete the structure. These top sections contain numerous perforations through which the air will emerge and pass up through the fuel on the grate. These improved grate bars .are capable of being cleaned with great facility, it being only necessary to remove the front ones of the top sections 21, when the accumulated fine ashes will instantlybe blown out, after which the furnace may be restored to operative condition by merelyreplacing thesaid top sections.

I prefer to make a grate of alternately hollow bars and solid bars. The solid bars 25 are made of substantially the same width as the hollow bars and also contain perforations through which the air which enters the ashpit through the front doors of the furnace may pass up through the fuel and also from which the ashes may descend into the ashpit. The top surfaces of these bars preferably have the same general form and appearance as the hollow grate-bars.

As will be apparent, the invention principally relates to the hollow grate-bars and the means or methods of attaching, supporting, and manipulating them. As will be readily understood, the upper surfaces of these bars may be easily renewed from time to time, as the same burn away, by removing the old burned top sections 21 and replacing them with new ones. The hollow bars as a whole are easily and closely attached to the airtrunk 17 by means of the flanges 80, which pass down behind the Wings 18. The surfaces of these flanges and wings are tapered where they come together, so that when assembled a tight union is formed between them. By putting in a little thinly-mixed fire-clay air-tight joints are easily secured.

The air is supplied from the blast-fan 40, from the nozzle of which a pipe 14E leads to and communicates with one end of the airtrunk 17. Said air-trunk communicates with the open ends of all the hollow grate-bars, and thus a suitable supply of air under pressure-is furnished throughout the entire area of the grate-surface. As this air-trunk rests on the bridge-wall, no pipes or other interfering parts extend into the ash-pit or elsewhere where they would constitute an obstruction.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is-

The combination, in a furnace, of an airtrunk extending across one side of the combustion-chamber having openings in one side and wings alongside said openings, hollow grate bars having open ends and flanges alongside of said open ends adapted to pass bebind the Wings on the air-trunk whereby the parts are firmly united, said hollow gratebars being tapered uniformly toward the other end and provided'with sectional perforated removable tops, and other grate-bars interposed alternately between said hollow gratebars and together therewith and with the airtrunk forming the floor to the combustionchamber.

In witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 1st day of October, A. D. 1902.

SYLVESTER P. GREY. 

